This invention relates generally to electric power transmission and distribution networks, and more particularly the invention relates to apparatus for washing electrical insulators in such networks.
Powerlines for the transmission of electric power are supported by electrical insulators from support towers. Similar electrical insulators are used with transformers in power transmission and distribution substations.
Such insulators typically comprise a plurality of serially-connected or stacked ceramic discs. The undulating surfaces of the discs increase the outer surface from the grounded support tower to the energized line, thus increasing the impedance of the insulator. Each disc also provides some rain protection for the discs thereunder.
Contaminants such as dirt and salt can build up on the insulator surfaces. When exposed to the moisture from dew, frost, or light rain, the dampened contaminants can conduct current and lead to an electrical failure, or flashover, of the insulator. Most insulator designs depend on wind and rain to clean the insulator surfaces, but, when the natural cleaning is insufficient, other methods are required to clean the insulators. Further, it is highly desirable and often imperative that this cleaning be done while the equipment or line is energized. Additionally, the cleaning must be accomplished without causing an electrical flashover and preferably without contaminating nearby areas with the cleansing material.